Question

I'm stuck with the problem below and wondering is someone out there will be able to help. I have added comments to the code to make it self-explanatory but let me know if you need more info or if the problem is unclear.

Thanks a lot in advance!

Edit: I've been asked to summarize the problem in text, so here it goes: under the circumstances described in the code below, Expression.Call(...) throws the following exception: "No method 'get_Item' exists on type 'System.Collections.Generic.List`1[System.Double]'"